Ena: planet of ends

When earth becomes the home of the United States the other countries are forced to go else were. But that was
2000000 years ago, Ena, a planet discovered 100 years ago that already had inhabitants is located in the outer reaches of the 20 galaxies already discovered by human kind. The whole planet is insane. They have gods and goddesses that are truly real with magnificent powers and strange warriors with animal instincts. Earth decided that they wanted to expand their empire and Ena wants nothing more than earth to leave them alone. A small group of friends want them gone, and will take a supposed test to become an amion, the animal warriors, but they don't even know what an amion truly is, neither do the amion's themselves.